Topdressing and ball roll

Anne Streich and Roch Gaussoin

Topdressing has become standard in golf course management. For years, many
golf course superintendents practiced heavy topdressing in the spring and
fall after core aeration. In the last 10 to 15 years, many of them have
switched to lighter, more frequent sand topdressing in their greens
management program.

Research has shown that greens that are not topdressed have poorer turf
quality than those that are topdressed as little as two times per year.
Greens that are not topdressed become thatchy and puffy, and can result in
scalping and shorter ball-roll distances.

With the continued demand from golfers for greater ball-roll distances,
superintendents have begun topdressing more often throughout the growing
season. Light, frequent topdressing is defined as application of 2 to 3
cubic feet per 1,000 square feet of material every 10 to 14 days throughout
the growing season. It is believed that this level of topdressing will
provide a smooth, firm and uniform surface, resulting in longer ball-roll
distances.

Topdressing is increasingly important on greens using the newer, aggressive
bentgrass cultivars. These bentgrass cultivars produce a denser canopy and
turf that is thatchier than the older bentgrass cultivars. The greater
resistance to the ball as it rolls over the grass blades may result in
shorter ball-roll distances. Shorter ball-roll distances and thatchy turf
surfaces are not acceptable to today's golfers. They want smooth, firm and
fast surfaces for putting.

Adding inches to ball roll
In-depth research on topdressing and ball-roll distance has been limited to
just a few projects. Much of the research that involves golf green
topdressing deals with thatch management and topdressing materials. But,
the studies that deal directly with topdressing's effect on ball-roll
distance can provide a better understanding of how topdressing can improve
ball-roll distance.

How much added distance should a superintendent expect to see from
topdressing? Research indicates that ball-roll distance difference would
have to be at least 6 inches greater-and more likely closer to 12 inches
greater-for a typical golfer to notice a difference. Anything less would
not warrant the added effort and expense of increased topdressing because
few players would detect the change. You should increase the topdressing
frequency only if it significantly increases the quality or health of the
green.

A University of Nebraska study has shown that greens topdressed seven to eight times during the growing season at 2.7 cubic yards per 1,000 square feet p
roduced significantly longer ball-roll distances than those greens
topdressed in the spring and fall at 10.8 cubic feet per 1,000 square feet.
The ball-roll distance of the light, frequent topdressing program was 8.1
feet compared with 6.9 feet for the twice-yearly topdressing program. Both
had nitrogen applied at 2 pounds per 1,000 square feet per growing season.

Other factors
Not only is frequency of topdressing important, you also must allow the
topdressing to be worked into the surface. Verticutting opens the turf so
that the topdressing can easily settle in. But don't overdo it.

Researchers in a University of Nebraska study conducted on several golf
courses in Nebraska, South Dakota and Iowa, found that a moderate frequency
of verticutting and topdressing-two to six timesper year-was preferable to
a more aggressive program of 12 to 16 times a year.

The more aggressive program caused continual disruption of the surface of
the green, so a smooth surface never formed. But moderate topdressing and
verticutting allowed the topdressing material to be worked into the canopy
to produce a firm, smooth putting surface.

Research at The Pennsylvania State University supports the conclusion that
the topdressing must be worked in to achieve a smooth putting surface.
Researchers found that both light and heavy topdressing decreased ball roll
distance initially. But after topdressing material had time to work itself
into the canopy, ball roll distance increased.

For the first eight days, a ball lost up to 5 inches of roll with light
topdressing and 9 inches with heavy topdressing. But after the topdressing
material worked itself into the canopy, ball roll increased 6 inches with
light topdressing and 15 inches with heavy topdressing.

For this reason, you should apply topdressing material 10 to 12 days before
you want the surface to achieve its best surface (for member-guest or other
big events). This gives the topdressing material enough time to settle into
the turf. Dry topdressing material will easily settle into the turf canopy
with just a light brushing or light irrigation.

Is it worth the effort?
Topdressing provides a better surface for ball roll because it creates a
firm, smooth, uniform surface that exerts minimal resistance on the ball as
it rolls across a green. Rather than applying topdressing material heavily
at the beginning and end of the growing season and hoping that it provides
an adequate surface throughout the golf season, light, frequent topdressing
has been used to provide a better surface to putt on throughout the growing
season.

Golfers can play on greens managed with a light, frequent topdressing
system right after topdressing applications. Playing on greens managed with
heavy, infrequent topdressing is difficult right after applications because
they have a thick layer of sand that needs to be worked in. Also, piles of
sand often persist for up to four or five days after applications.

When considering more topdressing to improve ball-roll distance, you should
keep in mind the average golfer's ability to detect a change of ball-roll
distance. Most likely the change would have to exceed 6 inches, and
probably be closer to 12 inches, before a golfer would be able to notice.

Increasing ball-roll distance by 5 or 6 inches by increasing topdressing
frequency from six to 10 times per year probably would not be a sound
financial decision unless you were seeing improved turf quality or health.
The added time and money spent on the four additional applications would
not give you a significant increase in ball roll distance.

A good rule to follow for topdressing greens to get maximum ball roll
distance and highest green quality is to topdress at a light rate once a
month during the growing season.

Anne Streich is an extension horticulturist and Dr. Roch Gaussoin is an
extension turfgrass specialist at the University of Nebraska (Lincoln,
Neb.).